Device for the limitation of the movements of an elastically suspended drive unit



United States Patent [72] Inventors Heinz Krauss Appl. No. FiledPatented Assignee Priority Korb Kreis, Waiblingen;

Wolfgang Sautter, Heimerdlngen, Wuerttemberg; Uwe Llgniez, Waiblingen,Germany June 13, 1968 Dec. 22, 1970 Daimler-Benz AktlengesellschaftStuttgart-Unterturkheim, Germany June 15, 1967 Germany DEVICE FOR THELIMITATION OF THE MOVEMENTS OF AN ELASTICALLY SUSPENDED DRIVE UNIT 24Claims, 9 Drawing Figs.

US. Cl 180/64, 248/9 Int. Cl. 860k 5/12 Field of Search 1 80/64;

[56] References Cited UNITED STATES PATENTS 2,080,435 5/ 1937 Paton180/64 2,084,080 6/1937 DAubarede 180/64 2,270,902 1/1942 Rubissow 248/8X 2,406,256 8/1946 Roche 248/9 3,244,386 4/1966 Bourgeois 248/9 FOREIGNPATENTS 603,643 6/1948 Great Britain 180/64 Primary Examiner- BanjaminHersh Assistant Examiner-Milton L. Smith Attorney-Craig, Antonelli,Stewart & Hill ABSTRACT: An arrangement for limiting the strokemovements of an elastically suspended drive unit, in which the elasticabutment or abutments are so arranged in or nearly within a verticallongitudinal center plane of the drive unit that in the verticaldirection they come into abutment after traversing a limited, freedeflection path whereas in the direction of rotation about thelongitudinal axis, i.e., in particular under the effect of the enginetorque, normally, they fail to come into abutment.

PATENTED DEB22 mm 3.54 35 sum 1 UF 2 I INVENTORS HEINZ muss WOLFGANGSAUTTER UWE LIGNIEZ ATTORNEYS DEVICE FOR THE LIMITATION OF THE MOVEMENTSOF AN ELASTICALLY SUSPENDED DRIVE UNIT The present invention relates toa device for the stroke limitation of an elastically suspended driveunit. Stops for the stroke limitation were arranged heretofore laterallyof the engine with as large as possible a lever arm' with respect to theengine longitudinal axis in order to absorb the torques and torquefluctuations occurring during operation, and were so adjusted that theycame into abutment under the torque. As a result thereof, humming'noisesoccurred in the vehicle interior by reason of the sound transmission,which considerably impaired the driving comfort.

It is the aim of the present invention above all to prevent or at leastfar-reachingly reduce the transmission of engine noises to the vehiclebody. This is achieved according to the present invention in that theelastic stop or stops are so arranged in or nearly within a verticallongitudinal center plane of the unit that in the vertical directionthey come'into abutment after a limited free oscillation or deflectionpath but do not come into abutment in the direction of rotation aboutthe longitudinal axis of the unit, i.e., in particular under the effectof the engine torque. A noise or sound transmission as with the priorart types of constructions used heretofore, operating, for example, withengine movement shock absorbers or engine mounting rods is avoided inthe state of quiescence of the unit by reason of the free swinging orpivot path. As compared to engine movement shock absorbers, thearrangement according to the present invention additionally causesconsiderably smaller costs with the same reduction of engine paths.

The elastic stop or stops may be located within a vertical transverseplane extending through the center of gravity of the drive unit, i.e.,below or above the center of gravity. However, preferably the-stops orabutments are arranged in two transverse planes, in particular at theforward and at the rear end of the unit, approximately'in a verticalplane containing the engine longitudinal axis and below the enginelongitudinal axis. As a rule, it is thereby insignificant whether thecrankshaft axis, the main inertia axis or a pivot bearing support axisof the engine or engine unit is assumed as engine longitudinal axisbecause in general, all of these axes are disposed or are nearlydisposed in a common vertical longitudinal plane.

A stop or abutment member freely adjustable into a center position isprovided for the limitation of the'free swinging or deflection path.However, depending on the type of construction and requirements, thefree swinging or deflection path can be selected differently and may benearly zero in the limit case. It has been found asparticularlyadvantageous if the free swinging or deflection path of theengine unit inrelatio'n to the remaining vehicle is larger in thedownward direction (for example, 3 to mm.) than in the upward direction(for example, 0.5 to 2 mm.). The elastic stop surfaces or abutmentselements may be arranged at the abutment part or at the counterabutmentpart or possibly also at both parts.

It is particularly advantageous to provide elastic abutments and/or afree swinging or deflection path, which are adjustable, so that afavorable play can be achieved and a subsequent correction thereof can,be undertaken. p

In a particularly preferred construction of the present invention, thefreely adjustable abutment part or parts areconnected without play withone of the parts to be supported in a limited manner, for example, withthe engine unit, and are connected with the other of these pans to besupported, for example, with a vehicle part, by means of elasticelements having slight resistance in the vertical direction whereby thelastmentioned part is provided with counterabutment elements, againstwhich the abutment part or parts rest after traversing the free swingingor deflection path. The connection with the first-mentioned part maytake place, for example, by means of connecting links or the likeprovided with adjusting means. For example, lateral elastic webelementsof rubber or the like serve for the connection with slightresistance with the second-mentioned part, which enable a free swingingand selfadjustment of the abutment part in the vertical direction. Suchtypes of weblike elements are also particularly advantageous when theabutment part itself consists completely or nearly completely of rubberor similar material.

Possibly, a further yieldingness, for example, a universal yieldingnesscan be interposed between the elastic abutments and'one of the parts tobe mutually supported. Additionally, the rubber forming the abutmentsmay be provided at the abutment surfaces with a layer of suitable, knownsynthetic resinous material in order that it is protected againstpremature wear by the universal movements (stirring movements) occurringduring the operation between the engine drive unit and the vehicle part.

Accordingly, it is anobject of the present invention to provide anarrangement for limiting the toand fro movements of an elasticallysuspended engine unit which obviates, by simple means, theaforementioned shortcomings and drawbacks encountered in the prior art.

It is another object of the present-invention to provide a device forlimiting stroke movements of an elastically suspended drive unit whichprevents'or at least far-reachingly reduces the transmission of sound tothe body and therewith into the vehicle interior space. i

A further object of the present invention resides in a device forlimiting the strokes of an elastically suspended drive unit whichconsiderably improves the driving comfort.

A still further object of the present invention resides in an engineunit suspension of the type described above which permits the attainmentof a favorable play with possible subsequent readjustment.

These and further objects, features, and advantagesof the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illustration only, several embodiments in accordance withthe present invention, and wherein:

FIG. 1 is a schematic side elevational view of the overall arrangementof an engine drive unit in accordance with the present invention;

FIG. 2 is a side elevational view, partly in cross section and on anenlarged scale, of a stroke-limiting arrangement in accordance with thepresent invention, corresponding approximately to the forwardstroke-limiting device of FIG. 1; 7

FIG. 3 is a side elevational view of FIG. 2, partly in cross section,taken along line 3-3 of FIG. 4;

FIG. 4 is a cross-sectional view, taken along line 4-4 of FIG.

FIG. 5 is a cross-sectional view of a modified embodiment of astroke-limiting device according to the present invention with anelastic connection between the stroke-limiting element and the engineunit, taken along line 55 of FIG. 6;

FIG. 6 is a side elevational view of the device of FIG. 5;

FIG. 7 is a partial cross-sectional view of a modified embodiment of thearrangement of FIGS. 5 and 6;

FIG. 8 is a cross-sectional view through a still further modifiedembodiment of a stroke-limiting device according to the presentinvention with simultaneous rear support of the engine unit, taken alongline 8-8 of FIG. 9; and

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 8.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, and moreparticularly to FIG. 1, the engine unit generally designated therein byreference numeral 10 which consists of the engine 11, of the clutchhousing 12, and of the change speed gear 13, is suspended at the vehiclesuperstructure in a known manner, not illustrated in detail in FIG. 1,within elastic bearings, for example, by means of two laterally arrangedforward rubber bearings and one rearward rubber bearing arranged, forinstance, at the rear end of the change speed transmission, inparticular in such a manner that the engine unit 10 is able to swing orpivot about a longitudinal axis which is disposed in the verticallongitudinal center plane containing the crankshaft axis. Thelongitudinal pivot axis can be disposed thereby in the main inertia axisof the drive engine, i.e., can extend through the center of gravity Sthereof, either horizontally or at an inclination or also more or lessbelow or above the center of gravity.

According to the present invention, the vertical movement of the driveunit caused in particular by unevenesses of the road surface, is limitedin one, two or three points, A, B, C with free movability by thestroke-limiting devices generally designated by reference numerals 14,and 16, respectively. The limitation in the forward point A takes place,for example, at a forward crossbearer 17, the limitation in point B at arearward crossbearer 18 of a so-called drive stool which is elasticallyconnected with the remainder of the vehicle frame or vehicle body, andthe limitation in point C at a frame tubular member 19 whichaccommodates, for example, the change speed gear 13 and the cardan shaft20 and is fiangedly conhected to the change speed gear 13.

In general, a stroke limitation in all three points is not necessary.Under certain circumstances, a limitation within the center point Bapproximately below the center of gravity S suffices. However, alimitation in two points is more appropriate, particularly in the pointsA and C, possibly also in points A and B or in points B and C or in twoother points separated from each other by as large as possible adistance in the longitudinal direction of the engine.

FIGS. 2 to 4 illustrate a stroke-limiting device correspondingapproximately to that at point A in FIG. 1. A connecting member 22 ofthe stroke-limiting device is rigidly secured, for example, by means ofbolts 23, by welding or the like at a bearer member 21 of the engine 11.A square or rectangular guide part 25 of the steel core 26 is insertedin a vertical slot 24 of the connecting element 22 so as to beadjustable in the vertical direction. A threaded bolt 27 thereby clampstogether the steel core 26 and the connecting member 22 in the adjustedposition. The steel core 26 is surrounded by a rubber cushion 28 whichis additionally connected adheringly by means of webs 29 with theU-shapedstructural steel members 30-as also appropriately with the'steel core 26-by vulcanization or the like. The structural steelmembers 30 are connected by means of bolts 31, by welding or the likewith the crossrails 32 and 33 which, together with the structuralelements 30 surround the rubber cushion 28 in a framelike manner and,for example, in their turn are threadably secured at the forward drivingstool crossbearer 17 or form a part thereof.

The arrangement is thereby so made and the abutment part formed by thesteel core 26 and the elastic cushion 28 is thereby so adjusted withinthe slot 24 that the rubber cushion 28 has by means of its spherical orcurved surfaces 34 and 35 in the normal rest position of the vehicleand, of the engine a free play e, and e, which corresponds to the freeswinging or deflection path of the drive unit 10 or engine 11 relativeto the FIGS. 5 and 6 are again designated with the same numerals. Therubber cushion 28 is provided with protective and reinforcing members34a, 35a, thereby eliminating premature wearing of the rubber surface bythe action of friction on the parts of the crossrails 32, 33.- I 1 Incontradistinction to the preceding embodiment, the connection betweenthe rubber cushion 28 andthe engine ll.is realized in this embodiment bya connecting element 220 which is elastically connected with the engine11. The elastic connection takes place by meansrof two: ring-shapedrubber discs 36 and 37 which are interposed between a metal disc 38rigidly connected with the upper end of the connecting elevehicle or therespective vehicle part or driving stool part 17. If

the driving unit deflects in the vertical direction either downwardly orupwardly relative to the vehicle, the abutment member 26, 28 aftertraversing the free deflection path e, or e is pressed by means of theconnecting member 22 against the crossrails 32 or 33 effective ascounter abutment members, and the rubber or similar elastic material isdeformed whereby thelateral webs 29 maintain the connection with thestructural parts 30 or with the vehicle part 17 without opposing anysignificant resistance to the vertical movement of the abutment part 26,28. After termination of the deflection, the abutment part 26, 28returns into its noise-insulating center position in which is devoid ofany contact due to the play at e, and e In FIGS. 5 and 6, a modifiedembodiment of the present invention is illustrated, and moreparticularly, for example, in conjunction with a stroke-limitingarrangement approximately at the place B of FIG. 1. The same parts asthose in FIGS. 2 to 4 are again designated with the same referencenumerals.

in FIG. 7, a modified embodiment of the arrangement shown in FIGS. 5 and6 is disclosed. The same parts as those in ment 22a and two furthermetal discs 39 and 40 without metallic contact thereof whereby the metaldiscs 39 and 40 at their ends are threadably connected at the engine I]by means of bolts 41. The counterabutrnent part consisting of structuralsteel elements 30 and of the rails 32 and 33 is secured, for example, bymeans of bolts 42 at the crossbearer 18 of a driving stool or othervehicle part.

FIGS. 8 and 9 illustrate an embodiment which is particularly suitablefor a stroke limitation at the rear end of the drive unit, i.e., at therear end of the change speed transmission, approximately at the point C.

An approximately trapezoidally shaped, ringlike outer abutment part 45is secured at a rearwardly extending arm43 of the drive unit or changespeed transmission housing by means of a bolt 44; rubber cushions 46 and47 are secured by vulcanizing at the lower and upper inner surfaces ofthe outer abutment part 45. Furthermore, an inner abutment part 48 issupported by the outer abutment part 45 by means of lateral rubber webs49 which are adheringly and securely connected by vulcanization withboth the outer as also the inner abutment part. The inner abutment part48 is adjustable by a crossbolt 50, possibly in the direction of heightand is connected by clamping or the like with a U-shaped structural part51 which, in its turn, is secured at a crossbearer52'in the vehicleframe, of the body or the like by welding or in a similar, known manner.

If so desired, an inverse arrangement may also be provided in such amanner that the inner abutment part 48 is connected with the drive unitand the outer abutment part 45 with the vehicle, for example, with thebody frame, driving stool or the like. Furthermore, the abutment devicemay serve simultaneously or the usual elastic bearing support of thedrive unit in the vehicle in that, for example, the outer abutment part45 connected with the drive unit is supported on the crossbearer 52 orthe like by means of obliquely arranged rubber cushions 53 in such amanner that the abutment part 45 or the drive unit is able to pivotunder the engine torque about a longitudinal axis extending through thepoint P. By reason of the free deflection path e, and e; between theinner and the outer abutment part and by reason of the yieldingness ofthe web elements 49 offering slight resistance, these rotary movementsare permitted without difficulty whereas vertical movements between thetwo abutments parts or between the drive unit and the vehicle arelimited after traversing the free deflection path e, or e 98 2 by theelastic abutments of the rubber cushions 46 or 47.

While we have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to a person skilled in the art, and we therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

I claim:

1. An arrangement in a vehicle for the stroke limitation of anelastically suspended drive unit having a longitudinal pivot axis,comprising:

a plurality of elastic abutment means operatively associated between thedrive unit and the vehicle, and located at a distance with respect tothe longitudinal pivot axis;

said elastic abutment means being located at least approximately in avertical longitudinal plane of the drive unit so as to provide relativemovement in the vertical direction in case of vertical impacts andrelative movement in an approximately horizontal direction in case ofrotary oscillations about the longitudinal pivotaxis; said elasticabutment means having alimited free deflection path between the driveunit and the vehicle;

means for mounting said elastic abutment means with respect to the driveunit and the vehicle; whereby said elastic abutment means comes intoabutment in a vertical direction after the'limited free deflection path;and t at most, only approximately minor abutment occurs between saidelastic abutment means in the case of rotary oscillations about thelongitudinal pivot axis under the effect of engine torque.

2. An arrangement according -to claim 1, wherein each elastic abutmentmeans is arranged above the center of gravity point of the drive unit.

3. An arrangement according to claim 1, wherein each elastic abutmentmeans is arranged below the center of gravity point of the drive unit.

4. An arrangement according to claim 1, wherein said elastic abutmentmeans are arranged in the forward and rear end area of the drive unit.

5. An arrangement according-to claim 1, wherein said elastic abutmentmeans are arranged in one of the forward and rear end areas and in azone of a vertical transverse plane of the drive unit, said planeextending substantially within the area of the center of gravity of thedrive unit.

6. An arrangement according to claim 1, wherein the free deflection pathof the drive unit relative to the vehicle is larger in the downwarddirection than in the upward direction.

7. An arrangement according to claim-l, wherein the elastic abutmentmeans are adjustable.

8. An arrangement according to claim 1, wherein the free deflectionpaths are adjustable.

9. An arrangement'having at least two parts to be mutually supported ina limited manner according to claim 1, wherein said mounting meansincludes at least one freely adjustable abutment part which isoperatively connected in the vertical direction substantially withoutplay with one of the two parts to be supported in a limited manner andis operatively connected with the other of the parts-by elastic meansoffering slight resistance in the vertical direction, and wherein saidother part includes counterabutment means against which thefirst-mentioned abutment part abuts after traversing the free deflectionpath.

10. An arrangement according to claim9, further comprising connectingmeans for connecting said abutment part with said one of the two partsto provide the play-free connection in the vertical direction.

11. An arrangement according to claim 10, wherein said connecting meansis rigidly connected with said one part.

12. An arrangement according to claim 10, wherein said connecting meansis connected with said one part with slight yieldingness.

13. An arrangement according to claim 12, wherein said connecting meansprovides a yieldingness in all directions.

14. An arrangement according to claim 10, wherein the connection betweensaid connecting means with the abutment part is vertically adjustableand the vertical adjustment is obtained by means of an elongatedaperture and clamping bolt means. 1

15. An arrangement according to claim 9, wherein the abutment part isconnected with the part, which is to be supported with a free deflectionpath relative thereto in the vertical direction, by elastic web meansoffering relatively slight resistance in the vertical direction.

16. An arrangement according to claim 1, wherein the elastic abutmentmeans is connected with the part, which is to be supaported with a freedeflection path relative thereto in the vertic direction, by elastic webmeans offering relatively slight resistance in the vertical direction.

17. An arrangement according to claim 16, wherein the elastic abutmentmeans are provided with a layer of synthetic resinous material.

18. An arrangement according to claim 16, wherein said elastic web meansextends substantially horizontally toward the part.

19. An arrangement according to claim 1, wherein at least one rubbercushion means provided with rigidly metallic core means is provided asabutment part carrying the elastic abutslight resistance in the verticaldirection, wherein said other part includes an outer abutment partsubstantially surrounding said inner abutment part, said outer abutmentpart being provided with said elastic abutment means against which theinner abutment part abuts after traversing the free deflection path.

22. An arrangement in a vehicle for the stroke limitation of anelastically suspended drive unit having a longitudinal axis, wherein theimprovement comprises elastic abutment means operatively associatedbetween thedrive unit and the vehicle, and further means for mountingsaid elastic abutment means at least approximately in a verticallongitudinal center plane of the drive unit so that said elasticabutment means comes into abutment in a vertical direction after alimited free deflection path whereas normally no abutment occurs betweensaid abutment means in the direction of rotation about the longitudinalaxis of the drive unit under the effect of the engine torque, saidfurther means includes at least one freely adjustable abutment partwhich is operatively connected in the vertical direction substantiallywithout play with one of the two parts to be supported in a limitedmanner and is operatively connected with the other of the parts byelastic means offering slight resistance in the vertical direction, saidother part includes counterabutment means against which thefirst-mentioned abutment part abuts after traversing the free deflectionpath, wherein the abutment part is connected with the part, which is tobe supported with a free deflection path relative thereto in thevertical direction, by elastic web means offering relatively slightresistance in the vertical direction.

23. An arrangement according to claim 22, wherein the other abutmentpart having a free deflection path to the one abutment part is connectedwith the associated part to be supported by the interposition of elasticmeans.

24. An arrangement according to claim 23, wherein the interconnectedelastic means serve simultaneously for the elastic support of the driveunit at the vehicle frame.

